1.5 FOOD CONSTITUENTS
Food is composed of the following five constituents:
§ Carbohydrates
§ Fats
§ Proteins
§ Minerals
§ Vitamins
Carbohydrates:
Carbohydrates used in cooking include simple sugars such
as glucose (from table sugar) and fructose (from fruit) and
starches from sources such as cereal flour, rice, arrowroot
and potato
Fats:
Fats and oils come from both animal and plant sources. In
cooking, fats provide tastes and textures. When used as the
principal cooking medium (rather than water), they also allow
the cook access to a wide range of cooking temperatures.
Common oil-cooking techniques include sauteing, stir-frying,
and deep-frying. Commonly used fats and oils include butter,
olive oil, sunflower oil, lard, beef fat (both dripping and
tallow), rapeseed oil or canola, and peanut oil. The inclusion
of fats tends to add flavour to cooked food.
Proteins:
Edible animal material, including muscle, offal, milk and egg
white, contains substantial amounts of protein. Almost all
vegetable matter (in particular legumes and seeds) also
includes proteins, although generally in smaller amounts.
These may also be a source of essential amino acids.
Minerals:
Minerals are the chemical elements required by living
organisms, other than the four elements carbon, hydrogen,
nitrogen, and oxygen which are present in common organic
molecules. Sometimes these "minerals" come from natural
sources such as ground oyster shells. Sometimes minerals
are added to the diet separately from food, such as mineral
supplements, the most famous being iodine in "iodized salt."
Other minerals are calcium, chloride, magnesium,
phosphorus, potassium, sodium and sulphur. These minerals
are obtained from milk, other dairy products, cereals,
legumes, bone meal, meat, fish, all fruits, vegetables, table &
sea salt etc.
Vitamins:
Vitamins are essential for the normal growth and
development. It is a key nutrient that the body needs in small
amounts to grow and stay strong. Examples are vitamins A,
C, and E. Vitamins are found in many fruits and vegetables;
especially green peppers, citrus, strawberries, tomatoes,
broccoli, leafy greens, potatoes, animal foods; such as liver
whole milk etc.
1.6 EFFECTS OF COOKING
The effect of cooking upon the food constituents are
below:-
1.6.1 Action of Heat on Carbohydrates
The interaction of heat and carbohydrate is complex. Longchain
sugars such as starch tend to break down into more simple
sugars when cooked, while simple sugars can form syrups. If sugars
are heated so that all water of crystallisation is driven off, then
caramelisation starts, with the sugar undergoing thermal
decomposition with the formation of carbon and other breakdown
products producing caramel.
An emulsion of starch with fat or water can, when gently
heated, provide thickening to the dish being cooked. In European
cooking, a mixture of butter and flour called a roux is used to thicken
liquids to make stews or sauces.
1.6.2 Action of Heat on Proteins
When proteins are heated they become de-natured and
change texture. In many cases, this causes the structure of the
material to become softer or more friable - meat becomes cooked.
Cooking at ordinary temperatures renders protein foods more
digestible. At high temperatures the protein itself gets denatured thus
making it of nutritive value. In some cases, proteins can form more
rigid structures.
1.6.3 Action of Heat on Fats
Fat melts when it comes in contact with heat. If heated to a
very high degree for a long time, fats undergo partial decomposition
and fatty acids and glycerol are produced. Glycerol further
decomposes into caroling which is an irritating compound to the
digestive system. When fat heated for long time at too slow
temperature it thickens, becoming gummy. This condition is known
as polymerization, and fat that has reached this stage is no longer fit
for use.
1.6.4 Action of Heat on Minerals
There is no appreciable loss of minerals due to cooking.
Some minerals are made more readily available by cooking.
1.6.5 Action of Heat on Vitamins
There is some unavoidable loss of vitamins during cooking.
The loss is considerable in respect of thiamine and vitamin C.
Vitamin A and D are not destroyed by the ordinary methods of
cooking. Vitamin B may be destroyed during cooking if cooked at
high temperature. The use of baking soda in cooking causes further
destruction of vitamins.
1.7 EFFECTS OF COOKING ON DIFFERENT TYPES OF
INGREDIENTS
Cereals:
Rice is washed before cooking. Excessive washing
removes the water-soluble vitamins and mineral. The
proactive of cooking rice in large quantities of water and
draining away the excess of water at the end of cooking
leads to further loss of B-group vitamins and minerals.
Rice, therefore, must be cooked with just enough water so
that all the water is absorbed at the end of cooking-this is
usually 2 or 2 ½ times the volume of rice. All cereals (eg.
water flour) absorb water and during cooking the starch
granules swell up and burst. This renders the digestion of
starch rapid and complete.
Pulses:
Pulses are rich in protein (20 to 25 per cent). They also
contain small quantities of starch. It is very important to boil
pulses very thoroughly. T his destroys the antitypic
substance present in them.
Green Leafy Vegetables:
Green leafy vegetables are prized for vitamins and
minerals. The vitamin A which occurs in the form of
thiamine and vitamin C are partially destroyed by cooking.
If the cooking water is drained away, there will be loss of not
only vitamins but also minerals. It is therefore
recommended that green leafy vegetables should be
cooked in a small amount of water and for the proper length
of time. Baking soda should not be used to hasten cooking.
Other Vegetables:
Vegetables like potatoes should be cooked with their outer
skin intact; this retains all the vitamins and minerals
contained in them. As a rule, vegetables should be cooked
in a small amount of water to prevent loss of vitamins and
minerals. They can also be cooked by steaming.
Cooking of Fruits:
Most fruits are eaten fresh and raw. This makes the
vitamins present in fruits easily available. Fruits can also be
cooked by stewing; this will result in loss of some vitamins,
particularly, vitamin C.
Cooking of Meat:
Meat is cooked in a number of ways. While cooking, meat
coagulation of protein is at 60°C.
· There is reduction in water content; consequently there
is shrinkage of meat,
· Collagen which is a protein of the connective tissues is
changed into gelatin,
· Elastic, which is also component of connective tissue is
not affected,
· The fat of meat melts
· There is loss of mineral in cooking water but this water
can be used as soup or gravy,
· Loss of B-group vitamins especially thiamine.
sCooking of Fish:
Fish contains so little connective tissue, that the cooking
time is very short. The proteins coagulate at 60°C.
Cooking of Milk:
When milk is heated, a scum consisting of fat, forms on the
surface. This makes it difficult for steam to escape; hence
milk boils over easily. Some of the lactalbumin sticks to the
sides and bottom. Prolonged boiling alters the taste of milk.
The cooked flavour is due to burning or caramelization of
milk sugar. There is destruction of thiamine and vitamin C
during boiling. Milk, which is already a poor source of
vitamin C becomes poorer at the end of boiling. Boiling
destroys enzymes and the useful lactic acid bacteria
present in milk.
Cooking of Eggs:
The albumin of the egg begins to coagulate at 60°C; and
solidifies at 64°C – 65°C. At boiling point (100°C), the
albumin becomes tough. However there is little change in
the nutrients present in the egg.
CULINARY ART
Culinary art is the art of cooking. The word "culinary" is
defined as something related to or connected with cooking or
kitchens. A culinarian is a person working in the culinary arts. A
culinarian working in restaurants is commonly known as a cook or a
chef. Culinary artists are responsible for skillfully preparing meals
that are as pleasing to the palate as to the eye. Increasingly they are
required to have knowledge of the science of food and an
understanding of diet and nutrition. They work primarily in
restaurants, fast food franchises, delicatessens, hospitals and other
institutions and corporations. Kitchen conditions vary depending on
the type of business, restaurant, nursing home etc.
1.8.1 Careers in Culinary Arts
The culisnary arts profession is made up of people who work
either directly or indirectly in the preparation and service of food
items in the public or private sector. They work in a range of
establishments including, but not limited to hotels, full-service
restaurants, private clubs, corporate dining, institutional catering,
caterers, and home meal replacement (carry-out). With the
increased demands of the consumers for nutrition, quality,
sophistication in all parts of the culinary industry, today's culinary
professional needs to be well trained and prepared to meet the
consumers demands.
1.9 CUISINE
Cuisine is a specific set of cooking traditions and practices,
often associated with a specific culture. Religious food laws can also
exercise a strong influence on cuisine. A cuisine is primarily
influenced by the ingredients that are available locally or through
trade. For example, the American-Chinese dish chop suey clearly
reflected the adaptation of Chinese cuisine to the ingredients
available in North America.
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